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Dense coding scheme using superpositions of Bell-states and its NMR implementation

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Science china(physics,Mechanics & Astronomy) 2005年第1期48卷 57-67页

作者： ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key Laboratory for Quantum Information and Measurements, Department of physics, Tsinghua University, beijing 100084,{2. {3. for Quantum Information, Tsinghua University, beijing 100084,{2. Department of Materials Science and Engineering, beijing Normal University, beijing 100875,{2. Testing and Analytical {3., beijing Normal University, beijing 100875,{2. Department of physics, beijing Normal University, beijing 100875,{2. Key Laboratory for Quantum Information and Measurements Department of Physics Tsinghua University Beijing 100084 China center for Quantum Information Tsinghua University Beijing 100084 China Department of Materials Science and Engineering Beijing 100875 China Testing and Analytical center Beijing Normal University Beijing 100875 China Department of physics Beijing Normal University Beijing 100875 China

Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.

关键词： dense coding, superpositions of Bell-states, generalized Grover's algorithm, nuclear magnetic res-onance, quantum computer.

Studies of low-lying states of even-even Xe isotopes within the nucleon pair approximation

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Science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 103-108页

作者： ZHANG LiHua1, JIANG Hui1,2.& ZHAO YuMin1,3.4 1institute of Nuclear, Particle, Astrophysics and Cosmology, Department of physics, Shanghai Jiao Tong University, Shanghai 2.02.0, china 2.chool of Arts and Sciences, Shanghai Maritime University, Shanghai 2.013., china 3.10} of Theoretical Nuclear physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 73.000, china 4CCAST, World Laboratory, P.O. Box 873.,{13., china institute of Nuclear Particle Astrophysics and Cosmology Department of Physics Shanghai Jiao Tong University Shanghai China School of Arts and Sciences Shanghai Maritime University Shanghai China center of Theoretical Nuclear physics National Laboratory of Heavy Ion Accelerator Lanzhou China CCAST World Laboratory Beijing China

We study the relevance of nucleon pairs with higher spins, in addition to spin-zero and spin-two pairs (i.e., S D pairs), in low-lying states of even-even Xe nuclei. By including those higher-spin pairs in our configuration, we recalculate energy level schemes, elec trical quadrupole moments, magnetic moments and electric quadrupole transition rates, for low-lying states of even-even 12.-142.e nuclei. The agreement between our calculated results and the experimental data is substantially improved in comparison with previous studies.

关键词： nucleon pair approximation shell model configuration space low-lying states

The onset and advance of the Asian summer monsoon

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Science Bulletin 2006年第1期51卷 80-88页

作者： Lü Junmei1,2.4, ZHANG Qingyun1, TAO Shiyan1 & JU Jianhua3.1. State Key Laboratory of Numerical Modeling for Atmospheric Sci- ences and Geophysical Fluid Dynamics, institute of Atmospheric physics, Chinese Academy of Sciences, {2. 10002., china 2. Department of Atmospheric Sciences, Yunnan University, Kunming 650091, china 3. china Meteorological Administration Training Centre, {2. 100081, china 4. Graduate School of Chinese Academy of Sciences, {2. 10003., china State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Department of Atmospheric Sciences Yunnan University Kunming China Graduate School of Chinese Academy of Sciences Beijing China china Meteorological Administration Training Centre Beijing China

Based on the daily outgoing longwave radiation (OLR) data from National Oceanic and At- mospheric Administration (NOAA) satellites, the Cli- mate Prediction center’s merged analysis of pre- cipitation (CMAP) data and the National centers for Environmental Prediction/National center for At- mospheric Research (NCEP/NCAR) reanalysis dataset, the mean intraseasonal variability of the Asian summer monsoon (ASM) is investigated by using power spectrum analysis, band-pass filter, and diagnostic analyses. The processes of the onset and advance of monsoon over the southern part of Indo-{3. Peninsula, the east coast of Bay of Bengal, the South{3. Sea and the Indian subcontinent are explored. It is found that there is an abrupt change in OLR, precipitation and zonal wind during the onset and advance of the ASM. It is also indicated that the southern part of Indochina Peninsula and the adja- cent Andaman Sea is the region where the earliest onset of the ASM occurs in the 2.d pentad of May.

关键词： Asian summer monsoon intraseasonal variability onset advance.

Probing Nuclear Symmetry Energy with Giant Dipole Resonances in Finite Nuclei

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原子核物理评论 2009年第S1期26卷 181-184页

作者： CAO Li-gang1,3.MA Zhong-yu2.3.(1 institute of Modern physics,Chinese Academy of Sciences,Lanzhou 73.000,{2. 2.3. institute of Atomic Energy,beijing 102.13.{2. 3.center of Theoretical Nuclear physics,National Laboratory of Heavy Ion Research Facility in Lanzhou,Lanzhou 73.000,{2.) institute of Modern physics Chinese Academy of SciencesLanzhou 730000China center of Theoretical Nuclear physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China china institute of Atomic Energy Beijing 102413China center of Theoretical Nuclear physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China

The relationship between the centroid energies of the isovector giant dipole resonance of finite nuclei and the symmetry energy has been studied. It is found the excitation energies of the dipole resonance in finite nuclei are correlated linearly with the symmetry energy at and below the saturation density. This linear correlation leads to the symmetry energy at the saturation density at the interval 3..0 MeV ≤ S(ρ0) ≤ 3..0 MeV,and the symmetry energy at ρ = 0.1 fm-3.at the interval 2..2.2..5 MeV. It is proposed that a precise measurement of the dipole mode in nuclei could set up an important constraint on the equation of state for nuclear {3..

关键词： symmetry energy dipole resonance Pygmy resonance

Hard X-ray lags of Cygnus X-1 on short timescales

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 150-152页

作者： JIN Jing1,LU Yu2.3.QU JinLu2.& LI TiPei1,2.1 Department of Engineering {3. & center for Astro{3.,Tsinghua University,beijing 100084,china 2.Key Laboratory of Particle Astro{3.,institute of High Energy {3.,Chinese Academy of Sciences,beijing 100049,china 3.Graduate University of Chinese Academy of Sciences,beijing 100049,china Department of Engineering physics & center for Astrophysics Tsinghua University Beijing China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China

Calculating the time lags over different timescales using the cross-correlation technique may lead to a biased estimate of small *** a timescale for lightcurve binning,we propose to subtract the local average instead of the global average during the cross-correlation,in order to filter variations on timescales larger than the bin *** new method allows us to make an unbiased estimate of the time lags using RXTE/PCA data on timescales as small as-5 ms,where the Fourier technique becomes *** calculate the time lag spectra of Cygnus X-1 at different spectral states with the new method,and find that the source appears to have similar X-ray lags on small timescales independent of its spectral states.

关键词： spectral lags Cygnus X-1 data analysis

Fabrication and properties of the meander nanowires based on ultra-thin Nb films

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Chinese physics B 2014年第8期23卷 521-526页

作者：赵璐金贻荣李洁邓辉郑东宁 beijing National Laboratory for condensed {2.{3. Institute of Physics Chinese Academy of Sciences

We report the fabrication and the study of superconducting properties of ultra-thin Nb superconducting meander nanowires, which can be used as superconducting nanowire single-photon detectors （SNSPDs）. The ultra-thin （about 7- nm thick） Nb films are patterned into micro-bridges, and 100-nm wide meander nanowires by using e-beam lithography （EBL）. The average transition temperature （Tc） of the nanowires is about 4.8 K and the critical current density jc is about 2.8 × 10^6 A/cm2. Superconducting characteristics of the specimens at different applied magnetic fields up to 8 T （parallel or perpendicular to the specimen） are systematically investigated. The normalized temperature t （= T/Tc） dependences of the parallel critical field （HcⅡ） for both the micro-bridge and the meander nanowire are almost the same, following the Ginzburg and Landau （GL） formalism for ultra-thin films. However, in perpendicular field and in the vicinity of Tc （〉 0.95Tc）, the critical field Hc⊥ of the nanowire exhibits a down-turn curvature nonlinear temperature dependence while the micro-bridge displays a linear temperature dependence. The nonlinear behavior of Hc⊥ in the nanowire is believed to be due to the fact that in the vicinity of Tc the coherence length becomes larger than the line width. Additionally, the localization of carriers in the nanowire could also contribute to the nonlinear behavior. The resistive transitions could be described by the phase-slip model for quasi-one-dimensional system. Moreover, the hysteresis in I-V curve of the meander nanowires can be illustrated by a simple model of localized normal hotspot maintained by Joule heating.

关键词： Nb meander nanowire critical temperature critical field critical current

Propagation of interplanetary shock excited ultra low frequency (ULF) waves in magnetosphere-ionosphere-atmosphere——Multi-spacecraft “Cluster” and ground-based magnetometer observations

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Science china(Technological Sciences) 2010年第9期53卷 2528-2534页

作者： WANG ChengRui1,2.ZONG QiuGang1,3.& WANG YongFu1 1 institute of Space physics and Applied Technology,Peking University,{2. 100871,china 2.Sate Key Laboratory of Space Weather,Chinese Academy of Sciences,{2. 100190,china 3.center for Atmospheric Research,600 Suffolk Street,University of Massachusetts Lowell,MA 01854,USA institute of Space physics and Applied Technology Peking University Beijing China Sate Key Laboratory of Space Weather Chinese Academy of Sciences Beijing China center for Atmospheric Research University of Massachusetts Lowell USA

The ultra low frequency (ULF) wave in magnetosphere can act as an important means for solar wind energy inward *** paper quantitatively analyzes the propagation process of the ULF wave triggered by the interplanetary shock propagating from inner magnetosphere equatorial plane along magnetic field lines to the top of the ionosphere and below ionosphere propagating process and establishes a relatively complete magnetosphere-ionosphere-atmosphere propagation model which can be used to study the relationship between the amplitude of the ULF waves triggered by the interplanetary shock wave in magnetospheric space and the magnetic effect caused by the ULF *** a comparison with recent observations,we found that: in the event during November 7,2.04 that an interplanetary shock wave interacted with the magnetosphere,Cluster satellites observed that electric field fluctuations and the band-pass filtered result of ground stations meridional component had similar *** with the geomagnetic measurement near the footprints,we found that the electric field disturbance in the magnetosphere spread along the ground magnetic field lines in the form of the ULF waves and changed into geomagnetic *** result reveals that the ULF wave is in contact with the ground geomagnetic *** ULF waves couple with ionized components in ionosphere and spread to the ground in the form of electromagnetic *** this research,we believe that the magnetosphere,ionosphere and ground magnetic effects caused by interplanetary shock wave are the same physical phenomena responding in different *** on the overall consideration of entire electromagnetic response to the interplanetary shock wave,we found that the correlation between CLUSTER multi-satellite observation and geomagnetic station observation is due to the ULF wave propagated in magnetosphere-ionosphere-atmosphere system,and we quantitatively interpreted this response process

关键词： ultra low frequency (ULF) wave magnetic storm ionosphere IRI model interplanetary shock

Effects of 4DVAR with multifold observed data on the typhoon track forecast

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Chinese Science Bulletin 2003年第S2期48卷 93-98页

作者： WANG Yunfeng, WANG Bin, MA GANG & WANG Yushun 1. LASG, institute of Atmospheric physics, Chinese Academy of Sciences. {2. 10002., china: 2. National Satellite Meteorological center, {2. 100081. china Chinese Acad Sci Inst Atmospher Phys LASG Beijing 100029 Peoples R China Natl Satellite Meteorol Ctr Beijing 100081 Peoples R China

Effects of 4-dimension variational data assimi-lation (4DVAR) with multifold observed data on the typhoontrack forecast are studied, by using the MM5V3.model, theRTTOVS-5 model and their adjoint models. The data usedfor assimilation include large-scale background fields data,bogus data, cloud-derived wind data, satellite inverse data,and high resolution infrared radiation sounder data (HIRS).There are 5 typhoon cases are used to perform the numericalexperiments and assimilation experiments. The numericalresults show that with 4DVAR the initial fields can be greatlyimproved and the initial typhoon structure can be clearlydescribed.

关键词： multifold observed data 4DVAR typhoon track. DOI: 10.13.0/03.d0456

Some evidence of drying trend over northern china from 1951 to 2.04

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Chinese Science Bulletin 2006年第23期51卷 2913-2925页

作者： MA Zhuguo1,2.& FU Congbin1,2.1. Key Laboratory of Regional Climate-Environment for Temperate East Asia, Chinese Academy of Sciences, beijing 10002., china 2. START Regional {2. for Temperate East Asia, {3. of Atmos-pheric physics, Chinese Academy of Sciences, beijing 10002., china Key Laboratory of Regional Climate-Environment for Temperate East Asia Chinese Academy of Sciences Beijing China START Regional center for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The surface wetness index, Palmer drought sererity index and the retrieval of soil moisture over china were calculated using monthly precipitation and monthly mean surface air temperature. Based on the contrast analysis of the variation of the above three indices and precipitation, the dry/wet spatio-temporal pattern of northern china in the last 54 years was revealed, and the evidence of drying trend over northern china was analyzed, especially. The results show the following four facts: (1) The drying trend is the main characteristic of the eastern part of Northwest china and the central part of North china since the 1980s and it was enhanced in the last 15 years mainly due to the precipitation decrease and the temperature increase; (2. During the last 54 years, there was only one dry/wet shift at the interdecadal scale occurring in the eastern part of Northwest china and the central part of North china in the late 1970s, which was related to 1977/1978 global abrupt change, whereas there were three shifts in Northeast china, one was in the mid 1990s and the other two were in 1965 and 1983. respectively; (3. Unlike the variation trend of other subregions of northern china, the western part of Northwest china is currently located in a relatively wetting period, which is weak-ened due to the temperature increase; (4) The extreme drought frequency is obviously increasing in the eastern part of Northwest china, the central part of North china and Northeast china since the 1980s, which is closely related to the precipitation decrease and temperature increase in these subregions.

关键词：中国北方干燥趋向干旱索引气候背景